Start with the body application
Write down the full job: material carried, density, loading method, terrain, operating hours and any stationary equipment. The body supplier should confirm installation space and axle loading for the selected chassis. Do not assume that a Class 8 badge makes every build a highway tractor or heavy-haul combination.
Tandem chassis checks
Inspect both rear axles, suspension attachments, interaxle driveline, tires and frame for uneven wear or evidence of overload. Review any changes to wheelbase or body mounts. On equipment used at sites, include underside damage and contamination in the inspection rather than judging condition from cab appearance alone.
Document the ordered rating
Ask for the power rating, transmission tag, axle and suspension specification and the completed-vehicle labels. For a proposed trailer application, obtain the approved combination rating and hitch or fifth-wheel installation evidence. The published GVWR is a truck rating and does not supply a towing capacity.
Sources and reference scope
Reviewed September 9, 2026. Manufacturer facts are tied to the edition below; inspection and purchase-planning questions are editorial guidance.
Canadian MY2027 XL8 6×4. The wheelbase graphic contains overlapping values; it is not used here as a dimension authority.
Canadian XL8 application and Cummins L9 / Allison 3000 RDS context.
Select the truck model year and conventional or cab-over chassis before using installation drawings.